fix(ci): keep server alive across test steps, fix welcome screen test

.gitea/workflows/ci.yml

@@ -26,13 +26,15 @@ jobs:
       - name: Install Playwright + Chromium system deps
         run: npx playwright install chromium --with-deps
 
-      - name: Start static HTTP server
+      # Start server AND run tests in the same shell so the background
+      # process is guaranteed alive for the full test run.
+      - name: Start server & run tests
         run: |
-          npx --yes serve . -l 9090 &
+          npx --yes serve . --listen 9090 &
+          SERVER_PID=$!
           sleep 3
-
-      - name: Run smoke tests
-        run: npx playwright test --reporter=list
+          npx playwright test --reporter=list
+          kill $SERVER_PID 2>/dev/null || true
         env:
           APP_URL: http://localhost:9090